DISCLAIMER; This is a working document provided by the Centers for Disease Control and Prevention (CDC) 

technical support contractor, SC&A, for use in discussions with the National Institute for Occupational Safety and 

Health (NIOSH) and the Advisory Board on Radiation and Worker Health (ABRWH), including its Working Groups 

or Subcommittees. Documents produced by SC&A, such as memorandum, white paper, draft or working documents 

are not final NIOSH or ABRWH products or positions, unless specifically marked as such. This document prepared 

by SC&A represents its preliminary evaluation on technical issues.

NOTICE: This document has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 USC §552a and has been cleared for distribution. 

REVISED MEMORANDUM

TO: Subcommittee for Procedures Reviews; NIOSH; Ted Katz, DFO

FROM: Hans Behling, SC&A, Inc. 

DATE: August 14, 2017 

SUBJECT: Revision 1 to Resolution of Finding 3 under SC&A’s Review of DCAS-PER-047 

(GJOO)

This revision to the June 22, 2017, memorandum corrects a typographical error in the Tailings

calculation on page 3. 

Relevant Background 

In February 2015, SC&A submitted its draft report, A Review of NIOSH’s Program Evaluation 

Report DCAS-PER-047, “Grand Junction Operations Office” (SC&A 2015). Among findings 

identified in SC&A’s review of DCAS-PER-047 (NIOSH 2014) was Finding 3. Finding 3 

pertains to the National Institute for Occupational Safety and Health ‘s (NIOSH’s) modeled

annual intakes from inhalation and ingestion of uranium (U-238/U-235/U-234), radium-226 (Ra236), and thorium-230 (Th-230) during the decontamination and decommissioning (D&D) 

period (1988–2006) as cited in Table 6 of the revised Grand Junction Operations Office (GJOO) 

template and reproduced herein as Table 1.1

1 Templates (inclusive of the GJOO template) are not posted/available on the NIOSH website and can only be 

retrieved in conjunction with a completed Dose Reconstruction Report for a claimant who worked at the GJOO 

facility.

In support of these intakes, NIOSH only briefly mentioned the use of “five-hundred and sixtynine air sample measurements [that] were recovered for onsite D&D work, including both 

general area and breathing zone samples...” Given this limited information and the inability to 

assess/confirm NIOSH’s modeled intakes, SC&A identified Finding 3, which stated the 

following: “NIOSH provides neither the raw data nor a documented source for the 569 air 

sample measurements associated with D&D work for years 1989–2006.” 

Following discussions of SC&A’s findings with the Subcommittee for Procedure Reviews 

(PRSC) on February 18, 2015, and on April 28, 2015, NIOSH identified a total of 15 references 

from the Site Research Database (SRDB) that contained the 569 air sampling data during the 

D&D period.

At the request of the PRSC, SC&A conducted a limited review of said references and realized 

the enormity of a complete and independent review of these data. For example, Building 20 

 
Revised Memo – PER-047 Finding 3 Resolution 2 SC&A – August 14, 2017

NOTICE: This document has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 USC §552a and has been cleared for distribution. 

Health & Safety, SRDB Ref. ID 89938, contains 1,488 pages in support of survey data 

performed in Building 20. 

Given the time and effort that would be required to retrieve, sort, and analyze these data from 

among the 15 documents, SC&A issued a request (with approval of Ted Katz, DFO) to NIOSH 

on February 21, 2017, for summary air sampling data and their analysis. 

On February 21, 2017, NIOSH provided SC&A with the needed summary data in the form of a 

complex spreadsheet. A summary portion of the spreadsheet provided by NIOSH is enclosed 

here as Figures 1 and 2. 

Summary Data for D&D Air Samples. For the 569 air samples that represent the years 1989 

through 2001 of the D&D period, 519 samples showed air concentrations with a positive value 

(i.e., > 0). A plot of the natural log y of the 519 positive air samples yielded a distribution shown 

in Figure 1:

• At x = 0, this distribution yielded a y value of -29.25324 and for e-29.25324 corresponds to a 

50th percentile air concentration of 1.97×10-13 microcuries per milliliter (μCi/ml) of gross 

alpha activity.

• At x = 1.645, this distribution yielded a y value of -26.6525 and for e-26.6525 corresponds 

to the 95th percentile air concentration of 2.66E-12 μCi/ml of gross alpha activity.

Figure 2 identifies the lognormal fits of air sample data for each of the 13 years for 1989 through 

2001. Due to data limitations, years 1988, 1991, 1992, and 1993 could not be assessed; for the 

remaining nine years, the average 50th and 95th percentile gross alpha air concentrations 

corresponded to 2.68×10-13 μCi/ml and 1.906×10-12 μCi/ml.

In reviewing the collective versus annualized air concentration data, NIOSH came to the 

following conclusions, as stated in the revised GJOO template:

Initially, the air samples captures were analyzed as lognormal distributions yearby-year for the period 1989-2001, but the 50th percentiles were under the 

estimated MDA for about one third of the years. There was only one sample 

recovered for 1989 and none for 1991-1993....Due to the gaps described, the 

decision was made to analyze the air sample results collectively. The 95th 

percentile of the lognormal analysis was used to determine the intake rates to be 

assigned. The 95th percentile from the collective analysis resulted in intakes 

about 40% higher than the year-by-year analyses....This distribution is deemed 

to apply to any D&D period before or after the samples were collected. For 

example, the D&D was essentially complete by 2001, but Building 20 was 

demolished in 2006....The results are shown for both ore and tailings in Table 6. 

The ore values overestimate the doses from yellowcake by assuming that Ra-226 

and Th-232 are in equilibrium with U-238. [Emphasis added.]
Revised Memo – PER-047 Finding 3 Resolution 3 SC&A – August 14, 2017

NOTICE: This document has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 USC §552a and has been cleared for distribution. 

Assessment of Assigned Uptakes of U, Ra-226, and Th-230 during D&D

As shown in Table 1, annual inhalation and ingestion intakes were derived based on the 95th 

percentile of gross alpha air concentrations from the collective analysis of 519 air samples for 

(1) four job categories, (2) three radionuclide groupings, and (3) two source terms (i.e., ore and 

tailings).

As part of this review, SC&A evaluated all assigned intake values for the D&D period. For 

illustration, however, only the highest job category (i.e., operator) is assessed for the inhalation 

intakes of U, Ra-226, and Th-230 for each of the two source terms, since all other values are 

based on fixed ratios of these values.

Annual Inhalation Intakes for Operator 

Ore

• For the 95th percentile gross alpha air concentration of 2.66E-12 μCi/ml, U contributes 50.2 

percent and Ra-226 and Th-230 are each assumed to contribute 24.9 percent. 

• For annual inhalation, intakes assume breathing rate of 1.2 cubic meter per hour (m3/hr) and 

2,000 hours per year (hr/y). 

Uinhal. = (2.66E-12 μCi/ml) × (1.0E+06 milliliter per cubic meter [ml/m3]) × (0.502) × 

(1.2 meters per hour [m/hr]) × (2,000 hours per year [hr/y]) 

= 3.21E-03 microcuries per year (μCi/y) 

Ra-226 or Th-230 = (2.66E-12 μCi/ml) × (1.0E+06 ml/m3) × (0.249) × (1.2 m/hr) × 

(2,000 hr/y)

= 1.59E-03 μCi/y 

Tailings

• For tailings, the assumed fractional contributions to the gross alpha activity are 0.092 for U, 

and 0.454 for Ra-226 and Th-230. 

Uinhal. = (2.66E-12 μCi/ml) × (1.0E+06 ml/m3) × (0.092) × (1.2 m/hr) × (2,000 hr/y) 

= 5.87E-04 μCi/y 

Ra-226 or Th-230 = (2.66E-12 μCi/ml) × (1.0E+06 ml/m3

) × (0.454) × (1.2 m/hr) × 

(2,000 hr/y)

= 2.90E-03 μCi/y

SC&A’s Comments/Observation 

A comparison of values derived by SC&A above with corresponding D&D values cited in 

Table 1, confirms the use of an air concentration of 2.66E-12 μCi/ml. This air concentration of 
Revised Memo – PER-047 Finding 3 Resolution 4 SC&A – August 14, 2017

NOTICE: This document has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 USC §552a and has been cleared for distribution. 

gross alpha activity represents the 95th percentile of 519 air samples collected for years 1989 

through 2001 as shown in Figures 1 and 2. 

SC&A concurs with NIOSH’s methodology for the assignment of claimant-favorable internal 

exposures to unmonitored workers during the D&D period. 

SC&A, therefore, recommends closure of Finding 3. 

Table 1 shows that for two time periods (i.e., Sample Preparation 1975–1984 [ore] and Sample 

Preparation 1985–2003 [tailings]) intakes for the job category “General Labor” were one-half the 

intake of “Operators.” The reduced intake for “General Labor” is consistent with guidance in the 

GJOO template, which states the following: 

The data are assigned to all operations personnel. Intakes for other workers were 

determined using the ratios between job classes found in Section 8.5.1 of the 

Technical Basis Document: Site Profiles for Atomic Weapons Employers that 

Worked Uranium Metals (SRDB Reference 101251). Laborers received one-half 

the intake of operators, supervisors receive one-quarter, and administrative 

personnel receive one-tenth of the supervisor intake. The intakes are provided in 

the Table 6 and are assigned as a constant distribution. [Emphasis added.]

Observation 1. It is unclear and inconsistent why intakes for the job category “General 

Labor” are the same as for “Operator” for the D&D period of 1989–2006. 
Revised Memo – PER-047 Finding 3 Resolution 5 SC&A – August 14, 2017

NOTICE: This document has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 USC §552a and has been cleared for distribution. 

Table 1. Reproduction of Table 6, “Inhalation and Ingestion Intake Rates (1975–2006),” 

from the Revised GJOO Template

Job Categorya

Uranium Radium-226 Thorium-230

Inhalation

(μCi/yr)

Ingestion

(μCi/yr)

Inhalation

(μCi/yr)

Ingestion

(μCi/yr)

Inhalation

(μCi/yr)

Ingestion

(μCi/yr)

Sample Preparation 1975–1984 (Ore)

Operators For Sample Preparation 1975–1984 (Ore) 7.57E-03 1.59E-04 7.57E-03 1.59E-04 7.57E-03 1.59E-04

General Labor For Sample Preparation 1975–1984 (Ore) 3.79E-03 7.95E-05 3.79E-03 7.95E-05 3.79E-03 7.95E-05

Supervisors For Sample Preparation 1975–1984 (Ore) 1.89E-03 3.98E-05 1.89E-03 3.98E-05 1.89E-03 3.98E-05

Administrative For Sample Preparation 1975–1984 (Ore) 1.89E-04 3.98E-06 1.89E-04 3.98E-06 1.89E-04 3.98E-06

Sample Preparation 1985–2003 (Tailings)

Operators For Sample Preparation 1975–1984 (Ore) 5.74E-04 1.21E-05 2.83E-03 5.95E-05 2.83E-03 5.95E-05

General Labor For Sample Preparation 1975–1984 (Ore) 2.87E-04 6.03E-06 1.42E-03 2.98E-05 1.42E-03 2.98E-05

Supervisors For Sample Preparation 1975–1984 (Ore) 1.44E-04 3.01E-06 7.08E-04 1.49E-05 7.08E-04 1.49E-05

Administrative For Sample Preparation 1975–1984 (Ore) 1.44E-05 3.01E-07 7.08E-05 1.49E-06 7.08E-05 1.49E-06

Decontamination and Decommissioning 1989–2006 Natural Uranium (Ore, Yellowcake)

Operators For Decontamination and Decommissioning 1989–2006 Natural Uranium (Ore, Yellowcake) 3.21E-03 6.74E-05 1.59E-03 3.33E-05 1.59E-03 3.33E-05

General Labor For Decontamination and Decommissioning 1989–2006 

Natural Uranium (Ore, Yellowcake)

3.21E-03 6.74E-05 1.59E-03 3.33E-05 1.59E-03 3.33E-05

Supervisors For Decontamination and Decommissioning 1989–2006 Natural Uranium (Ore, 

Yellowcake)

8.02E-04 1.68E-05 3.97E-04 8.34E-06 3.97E-04 8.34E-06

Administrative For Decontamination and Decommissioning 1989–2006 

Natural Uranium (Ore, Yellowcake)

8.02E-05 1.68E-06 3.97E-05 8.34E-07 3.97E-05 8.34E-07

Decontamination and Decommissioning 1989–2006 (Tailings)

Operators For Decontamination and Decommissioning 1989–2006 Natural Uranium (Ore, Yellowcake) 5.87E-04 1.23E-05 2.90E-03 6.09E-05 2.90E-03 6.09E-05

General Labor For Decontamination and Decommissioning 1989–2006 

Natural Uranium (Ore, Yellowcake)

5.87E-04 1.23E-05 2.90E-03 6.09E-05 2.90E-03 6.09E-05

Supervisors For Decontamination and Decommissioning 1989–2006 Natural Uranium (Ore, 

Yellowcake)

1.47E-04 3.08E-06 7.25E-04 1.52E-05 7.25E-04 1.52E-05

Administrative For Decontamination and Decommissioning 1989–2006 

Natural Uranium (Ore, Yellowcake)

1.47E-05 3.08E-07 7.25E-05 1.52E-06 7.25E-05 1.52E-06

a. If worker duties cannot be determined, then the most claimant-favorable intake rate should be assumed.
Revised Memo – PER-047 Finding 3 Resolution 6 SC&A – August 14, 2017

NOTICE: This document has been reviewed to identify and redact any information that is protected by the Privacy Act 5 USC §552a and has been 

cleared for distribution.

Figure 1. Combined GJOO Air Sample Data

Combined (all samples)

(data copied from "Combined" sheet)

Year2

Last 

Count 

Concentra

tion 

(uCi/ml) Position Values Rank Quantile LN(value) SUMMARY OUTPUT

1998 BKG 1 0 0.00167 -2.93465 #NUM!

1998 BKG 2 0 0.003427 -2.70385 #NUM! Regression Statistics

1998 BKG 3 0 0.005185 -2.56327 #NUM! Multiple R 0.9533

1998 BKG 4 0 0.006942 -2.46025 #NUM! R Square 0.908781

1998 BKG 5 0 0.008699 -2.37817 #NUM! Adjusted R 0.908604

1998 BKG 6 0 0.010457 -2.30954 #NUM! Standard E 0.432901

1998 BKG 7 0 0.012214 -2.25032 #NUM! Observation 519

1990 NA 8 0 0.013972 -2.19808 #NUM!

1990 NA 9 0 0.015729 -2.15122 #NUM! ANOVA

1999 -1.98E-12 10 0 0.017487 -2.10866 #NUM! df SS MS F ignificance F

2000 -1.76E-13 11 0 0.019244 -2.06961 #NUM! Regression 1 965.2489 965.2489 5150.656 5.6E-271

1990 -7.31E-14 12 0 0.021002 -2.03349 #NUM! Residual 517 96.8874 0.187403

2000 -3.01E-14 13 0 0.022759 -1.99983 #NUM! Total 518 1062.136

2000 -7.47E-15 14 0 0.024517 -1.9683 #NUM!

2001 -3.61E-15 15 0 0.026274 -1.93861 #NUM! Coefficientstandard Erro t Stat P-value Lower 95%Upper 95%Lower 95.0%Upper 95.0%

1995 0 16 0 0.028032 -1.91054 #NUM! Intercept -29.2532 0.01941 -1507.11 0 -29.2914 -29.2151 -29.2914 -29.2151

1995 0 17 0 0.029789 -1.8839 #NUM! X Variable 1.581004 0.022029 71.76807 5.6E-271 1.537725 1.624282 1.537725 1.624282

1995 0 18 0 0.031547 -1.85853 #NUM!

1995 0 19 0 0.033304 -1.83431 #NUM!

1995 0 20 0 0.035062 -1.81112 #NUM!

1995 0 21 0 0.036819 -1.78886 #NUM! RESIDUAL OUTPUT DISTRIBUTION CALCULATIONS exp(y)

1995 0 22 0 0.038576 -1.76745 #NUM! x y (uCi/ml)

1995 0 23 0 0.040334 -1.74682 #NUM! ObservationPredicted YResiduals 50th %-tile 0 -29.25324 1.97E-13

1995 0 24 0 0.042091 -1.72692 #NUM! 1 -31.3774 -2.40993 84.1 %-tile 1 -27.67223 9.60E-13

1995 0 25 0 0.043849 -1.70767 #NUM! 2 -31.3604 -2.07314 95th %-tile 1.645 -26.6525 2.66E-12

1995 0 26 0 0.045606 -1.68904 #NUM! 3 -31.3436 -2.08335 GSD 4.86

1995 0 27 0 0.047364 -1.67097 #NUM! 4 -31.327 -2.08361 N 569 (observations)

1995 0 28 0 0.049121 -1.65343 #NUM! 5 -31.3106 -1.93067 n 519 (observations >0)

1995 0 29 0 0.050879 -1.63639 #NUM! 6 -31.2945 -1.57092

1995 0 30 0 0.052636 -1.61981 #NUM! 7 -31.2786 -1.50579

1995 0 31 0 0.054394 -1.60367 #NUM! 8 -31.2629 -1.44975

1996 0 32 0 0.056151 -1.58793 #NUM! 9 -31.2473 -1.40286

1995 0 33 0 0.057909 -1.57258 #NUM! 10 -31.232 -1.35375

1995 0 34 0 0.059666 -1.55758 #NUM! 11 -31.2168 -1.36043

1995 0 35 0 0.061424 -1.54293 #NUM! 12 -31.2019 -1.34493

1995 0 36 0 0.063181 -1.52861 #NUM! 13 -31.1871 -1.35022

1995 0 37 0 0.064938 -1.51459 #NUM! 14 -31.1724 -1.16026

1995 0 38 0 0.066696 -1.50086 #NUM! 15 -31.158 -1.039

1995 0 39 0 0.068453 -1.48741 #NUM! 16 -31.1437 -1.03427

-35

-33

-31

-29

-27

-25

-23

-21

-2 -1 0 1 2 3 4 5

Y

X Variable 1

X Variable 1 Line Fit Plot

Y

Predicted Y
Revised Memo – PER-047 Finding 3 Resolution 7 SC&A – August 14, 2017

NOTICE: This document has been reviewed to identify and redact any information that is protected by the Privacy Act 5 USC §552a and has been 

cleared for distribution. 

Figure 2. Summary of Lognormal Fits to GJOO Air Sample Data

Summary of Lognormal Fits to GJOO Air Sample Data

Year N n 50th 95th GSD Year Comments (Action limits/LLDs) Building Remediated Demolished D&D

(uCi/ml) (uCi/ml) 1 1996 1996

1989 1 1 NA NA NA 1989 Action limit = 7.0E-12; LLD for this sample was 3.36E-13 2 1997 1997

1990 37 32 1.94E-13 7.92E-13 2.35 1990 Action limit = 7.0E-12; LLDs ranged from 6.2E-15 to 8.6E-13 6 1992 1992

1991 2 2 NA NA NA 1991 Action limit = 7.0E-12; LLDs ranged from 2.81E-13 to 3.36E-13 7 1999 1999

1992 0 0 NA NA NA 1992 No data 7A 2001 2001

1993 0 0 NA NA NA 1993 No data 12/12A 2000 2000

1994 36 36 8.81E-13 2.69E-12 1.97 1994 Action limit = 7.0E-12 until 2/9/94 then 2.0E-11; LLDs not calculated 18 2001 2001

1995 32 20 1.26E-13 8.10E-13 3.10 Updated 1995 Action limit (DAC) = 1E-11; LLD, where calculated, was 1.61E-13 20 2000 2000

1996 19 17 1.42E-13 1.83E-12 4.74 Updated 1996 Action limit (DAC) = 1E-11 until 2/2/96 then 7.0E-12; 2/21/96 5.0E-11 20 2006 2006

1997 12 11 2.84E-13 2.66E-12 3.89 1997 28 1999 1999

1998 37 29 7.30E-14 1.99E-12 7.45 1998 31 1992 1992

1999 188 185 1.90E-13 2.10E-12 4.31 1999 31A 1998 1998

2000 86 83 3.59E-13 2.34E-12 3.12 2000 Action limit (DAC alpha) = 2E-11; MDAs calculated by Protean PC 32 2000 2000

2001 119 114 1.61E-13 1.88E-12 4.46 2001 33 1998 1998

All 569 519 1.97E-13 2.66E-12 4.86 34 1996 1996

Averages for years with data: 2.68E-13 1.90E-12 35 1998 1998

Mutty doesn't like 50th less than MDA (assumed to be 1.61E-13) 36 1996 1996

N = the number of observations 37 1992 1992

n = the number of observations >0 39 1992 1992

Zeros were ranked, but not fit 42 2000 2000

The data fit was the last count recorded. 44 1994 1994

Where values were recorded as less than some numerical value, 46 1999 Final survey 2005 1999

the numerical value was fit. (Re-calculated 1995 with LLDs where listed) 52 1994 1994

Most of the data was low enough that it was not recounted 62 2001 2001

at 7 days or longer as an official "record count." 938 2000 2000

Samples were generally recounted if they exceeded 10% of an Action Limit. 3022 1999 1999

At least for a period of time, samples were recounted until 3022 2000 2000

they were <5% of the action limit or DAC. 27 26 without 2006

Most samples were only counted once or twice (original, recount).

1989 value was 1.45E-12 uCi/ml Year Remediated Demolished Air Samples Year Buildings Air Samples

1991 values were 1.50E-13 and <2.81E-13. 1989 0 0 1 1989 0 1

Substituting MDA for years wo data: 1990 0 0 37 1990 0 37

1.61E-13 1991 0 0 2 1991 0 2

1.94E-13 1992 0 4 0 1992 4 0

1.61E-13 1993 0 0 0 1993 0 0

1.61E-13 1994 0 2 36 1994 2 36

1.61E-13 1995 0 0 32 1995 0 32

8.81E-13 1996 0 3 19 1996 3 19

1.26E-13 1997 1 0 12 1997 1 12

1.42E-13 1998 0 3 37 1998 3 37

2.84E-13 1999 4 0 188 1999 4 188

7.30E-14 2000 5 1 86 2000 6 86

1.90E-13 2001 0 3 119 2001 3 119

3.59E-13 10 16 569 26 569

1.61E-13

average: 2.35E-13

0

1

2

3

4

5

6

7

8

9

10

0

20

40

60

80

100

120

140

160

180

200

198919901991199219931994199519961997199819992000

Buildings

Air Samples

Year

Air Samples & Buildings D&Ded by Year

Buildings Air Samples

0

20

40

60

80

100

120

140

160

180

200

0

1

2

3

4

5

6

7

8

9

10

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001

Air Samples

Buildings

Air Samples & Buildings D&Ded by Year

Demolished Remediated Air Samples
Revised Memo – PER-047 Finding 3 Resolution 8 SC&A – August 14, 2017

NOTICE: This document has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 USC §552a and has been cleared for distribution.

References

NIOSH 2014. Grand Junction Operations Office, DCAS-PER-047, Revision 0, National Institute 

for Occupational Safety and Health, Division of Compensation Analysis and Support, Cincinnati, 

Ohio. March 26, 2014.

SC&A 2015. A Review of NIOSH’s Program Evaluation Report DCAS-PER-047, “Grand 

Junction Operations Office,” Revision 1, SCA-TR-PR2015-0093, SC&A, Inc., Vienna, Virginia. 

February 10, 2015.

SRDB Ref.ID: 89938 Undated. Building 20 Health & Safety.